SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'df678136fd2f9a15cc46afeda4a34389ae25d4996deb1c73b4fa4d800fcc1857' 
  AND token = 'Xhsf5B/lO4L3bsHCpaQRnmseMV/7lr8HtW4ALGHanUo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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