SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b735950f60e94fda3cdeb18a04c5333c3fd7af2f4f12c21d35e9008f776b62ec' 
  AND token = '8/8vZ95+qM8W2ZqlIYuvdOYJL/LM3JXA/UABszS0hew=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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