SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bb5ce5e04865c695aae8122e9dd19e42907bb5339d714e32a55bbd7aa257ef91' 
  AND token = 'JFApN38q/5CbbqxXTtMHaSplO8sXXZBkU0yren/DKyU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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