SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fc2c0f76c0100aec8a17c8cc200c655618c2eb3231c4379c200ae6cc1911eef' 
  AND token = 'HOVd+Kl1shdcmIUuEIiB/fhR+As3TLqHUGgtRGivo7g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}