SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9371def40fd38f8b6bab729e9aec33c697bfdb4d0568330dbbcd9d32065017c6' 
  AND token = 'bIZ2He4IsN2u/eZsJ2f5oCWvny5NcygZbViOASskU+4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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