SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ade0f323c1b0da75ef9c45b725487a2fd34f29f2d96956cebe01f915bf854c9f' 
  AND token = '8Vj/6zNE1dljN0b1hY4JS3in9Sjwza9+hMXk2Jil9Lo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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