SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '38f9b67e63eee42837466e430abc3d0065413d2da7ab0108cb2909ebc53db7e8' 
  AND token = 'Hg6lUJTx7ZS1epB9uOKNuhLiuPOZ57DfxGzxxEybOfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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