SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '83e3d5a61dce44c008cf20f560c7e8cc4867aa3c5dd0646b68107d5d1defb2f0' 
  AND token = 'cBUJmhUWEZ1mlJ3dyYlK5IhQKCUB8n7jOk+YGuZcZzU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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