SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f2648d60b846c7cedf85c9a07e70b135bf300647ae56de8802f028eccf2626b7' 
  AND token = 'PREYtYo5Fklaw7iQfgFpQRnrPpJDy9s8JFhxlaXZGbg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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