SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb187bd3b472d744194f65e9fae7b717b51957693c059c34fce0101bd6654345' 
  AND token = 'WQZBZvaa65K3KqHAJFjRA0qxsu+CGtga8et3YNdZx/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00076

JSON explain

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