SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '28afc4d6689f8b1d1323b2a5c78d771cd2f8bb398a6583d678b8b3ae6a0c99fe' 
  AND token = 'Hm1pxkyTpGyZw69RF/9dVSjB3N9RWwfqIK+JmhZ81r4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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