SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'fe8e0bdab55a1ecd9efadbc229f641fdb5a722a81cbcac814741353ed41e9874' 
  AND token = 'mdf6DGfXJcwMwk0k322Xxmy3ASb+BNv5vqcFSAdBrwI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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