SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cf9d6d10941cc2c66afb81bdb2a12d00a3b08d4d08dc8915c4a9c232de0e3f69' 
  AND token = 'hNRfoT3st5Dj+lwSUwCsgaG1GVQE1nZAWtEsdYWbVWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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