SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2a037010bca6eb26922ab8879f42058cd791ecb6ba25cc6916288122bb00666' 
  AND token = '4ZEIEq5hgYeIIrZWlf6Bn/yWM7PadxymnS92JtQGRa8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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