SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c83ea564b4299d5a40610c8a2adb1b767636701e40e8a2629d7441992bb99ec7' 
  AND token = 'C4ruKArt3DSUtlbfrxwRWCrF1y8fQFiKmYA0dRKjl1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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