SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aaf950c26755165fbe87b0379c609e3b5981ea90523415122ae5b31d1e42805b' 
  AND token = 'NukClBrzThgwFMZT3RnFBuz+rsHeZSRLXrjUz9zoS84=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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