SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '74b7d5119c5fac6d08621a895f6cf96cbd8c34b2fc9f0914e2052872a8f9f22f' 
  AND token = '/n2p+OY3ZqrRZP6W0ogcqGvPfmAg/3wR/Pxtp7wqnZU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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