SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7221fd0e9685934d51692f279788a549c72fb8191fc85a2003c34fb9cabf492d' 
  AND token = 'zdrUvS03aRe42zdrZX8eeq2T5qnTNC+lehhHtjyXD+E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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