SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'eba49f89d84c484ca336ede78fd4d33171719d0d7484bcc1895363b761e27808' 
  AND token = '+vDLv1GHCj9P4DVjefxpW6zh5nqpUzI9qGMETVES14g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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