SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '368fbdc6b9d36b7f87cff7ee830321eb7b7a449944445a31af373e7e5d5d2676' 
  AND token = 'pDSXGs6UGp19/4EL6emdliU1jiUHG3DD3itgUQqg/gQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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