SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '60991cce6b269965397cd83240ff48f874dfe582824d7afc33f76a9b050e1d0f' 
  AND token = '+wTlUbWfM3r2gEYqoInL+4bZ++aPdZlTfoYTTcOrBDc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

JSON explain

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