SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1bff124d088875a7d8c54828f306f7a9ac39c27131d1e04708b130a74bf6a494' 
  AND token = '6Ooru0SeH4OjFt0E1K/SP0Lyg6uu50gFJgnEx58pYs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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