SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4b140260b44c0572e1a16f54363f61af68e7f1f74bc235001f38ffdb9307f56c' 
  AND token = 'dlCTTJFGzjbHFi2XpjqsELuU5Qo4z8YcF0T7C++DCDk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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