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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e75fc7b9e7547104f51ed8ba79d69824a8a1ade8e52176d9af9c179a50765ee9' 
  AND token = 'cBD5MzbOEDrfpVyeJGMNWLgHjNSxYMTD1EGdVG3eU8g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}