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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df9e769a7c5f2eecfc9fa728c41ebf5c69fb6beb92064a89850f0416ad8c321c' 
  AND token = '80DXl4/MgFtyLmQzO6NUyb+zGgOqg8l9pTx8Z0udkpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}