SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4ad47af78179c0d4468c6ce34faef2a5e08b4d7291c9441bb2e31d4ab46119f' 
  AND token = '1isVT6aQL+QeQXA97x+zhQs9Ou1DwBkEYiLyS0E0dKo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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