SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'f3dfa0ecf9bae7ff4719992205f2669aa3b04804283e0074eee1612ffd1fc2b9' 
  AND token = 'hZDSI1Te6YivbJnOhW0X5dYDOZe1UAUpefn0XSlVaTE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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