SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ca612de94a71eaa63a716087ffe17d6b6300a7cce06936ee31058a620733f013' 
  AND token = 'owAWRKoqLrZ8v8z2hST37Lwt17YdTgA48BnMR3KC9NY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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