SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'da3019314191e93ee9af927e479b0d9e97046f448db820eceb8b3e0d6bd935b7' 
  AND token = 'XWTuNErypvxiqV2STR5k8cvsfrl68Q3TSiENmJ0hG6Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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