SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4217d294dc5fc376377cd55c74e42594f0f83f122a129a8f46a1649b504f99ba' 
  AND token = 'qoZ9vCQMdlenTwqLniC7NCfogkDhBXsrWB22uvuqG8M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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