SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa28d8679f9c75a3f1c8635f27080625522371537f37ddc2fe3b3d893ab663f6' 
  AND token = 'lGQVTwKnG7lrJNuVgh4atI1tZYgVbkCOCTJcfiaEMNU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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