SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ce740965030090e7e146f51719f11100fce5cd9c9af3093629176dc237b09dab' 
  AND token = 'zUPU6lZsMJvtPobQawvb6TcMpoU0TCcNoxeN51uKEzo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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