SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '13880f3c078cf5394273535a8c0548b7a0858de662f602c112c7395aa7e81d79' 
  AND token = 'gHsVQSEVYGiegLjlC2YQFCFT6bK49DrBWxxY2TvQHz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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