SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'efc178be460329c4c498752b00b61677857d66fe29b0fa8c7e9e5014330641db' 
  AND token = 'PVzjU/nEkqZoVWZZh/+Jbwp2meCJkvxzqSA74vMVWo8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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