SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2a4c6a589f7162538eb0e8f9626b8c52188db695f282ed1d1448644a41bc4fa1' 
  AND token = 'XFhKTZIUj6/1kcA4yKdiBnGDwfjj3OrSVomw/rU9oeA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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