SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '985a98290417cc6113c0246f0c0ad5625d2b7b4f3f87f96e4a46f5ace6b7aace' 
  AND token = '57TBW5xBZqJ+oRRg2X3ljMeG+LDYYvYhDw6rI09B7Vs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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