SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82f0ca18b9a9138cba8c150dc948ef344287e7ed14b0e99a61fa4d3d3674fd4d' 
  AND token = 'Ln8swiDuZMP/tkug5uEbDz/AeRfw+IXjo0LL3ZhfTE8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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