SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b76e35954195625244757fe6e5194551b45bb2f79dd79efd22bc9c26d0179d71' 
  AND token = 'f3t3VnCgFMdbGwGTBtpNpxwnNiOQ0JJpXfvV1HbceVQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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