SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '393880a12e61a6d0ccc250ad88828392a3e1dde678e506474ea0a96315fe273e' 
  AND token = 'ZLKYANusDlSw3ZYjoGpl9XoIJfLwjKHtVcMd3hIRCRk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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