SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '54a04780fb38dc612e4d1966607ba75a2486ba68cd30ac44eab068e382e268f7' 
  AND token = 'CrI1JPl7UZNlEgfdQA0WJC5H//fmicA4SxoLzlz8PTU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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