SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c6731c3691875d61fce3b49c5cca32270ddb9072c85255b1f247430ea39bfa5a' 
  AND token = 'QsiQJcCDse2+hPdl6WkgVxg23TIFXEBTBOh/KApXLug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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