SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9be9bbc8c47cf2e62bec141eb82f2e144c203dade3ddf7cb2144247e6b2da572' 
  AND token = 'D16EevCh8zOkxDlGOhjpOCQFhpkjciwSYBMCsLNJexM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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