SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4359828389741eef33d7b85bf33e92ca39f96fbe4134bd0a4206f449e06212a4' 
  AND token = '+/lrwcQMnD/pJPYR83f47LxkVO4fslWy/PNG9Rq/M6I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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