SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'c10dc020d15d96584e0e4e741ff4bd9df753d7c3db0c957b9a7b45b96a333545' 
  AND token = 'vytGiWMExbigbzKlunc+ls1OdUvEMO2tMsNO1EmOATk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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