SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1b72f360f347a616a8a8e7799dd851ecdbf1931788a006cbde9c833fd418ad5' 
  AND token = 'RPEv+ZOMPBDaZgYdm9sGnvl7sqz/BHMAZO67/U4B8ow=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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