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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '281068d03944fd1daa0969f8c225d6471dd3e90f4796a4ef95f6c79f6744801a' 
  AND token = 'djXhVOSTvDEmpMTPWOqAt+jU5QpBcP2/aX+XHJk2fTk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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