SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '67dce1befc21b7d5b3f6d5ac6b3fa6f845c4276630b36a46f37d7e0316bf4ed3' 
  AND token = 'LK5BZZ96swX1KgR5io4aE3zZ6pe8m7gqu4Bz/n+ZJXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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