SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '304db1c645664edb882dfe8253ebd10e13bd9806635ad64bad709bf43ffac7ca' 
  AND token = 'w0iCo9TOA7uDpmzLUCSgMNl+JWStw23OjrqkDHQA+YE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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