SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b6aed4d5045d04f1c6cdc888aa484eb53b2e9413bdcef9d32303de99a2011cb' 
  AND token = 'nWxWBDOeTcJKpgGxJxodl/pQGkJRe9CbeHZ2jYpW0ew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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