SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'dc7df9e568b7129b0f62d651e94d303b27cb6b9aa273a52906250087d07268c3' 
  AND token = 'HmnVlFz2tTMGxbupYLKaFK9aTJT3KhYB+hZAr8VO2Pg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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