SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '7ad1c57fec1a9252a17e5e497b332c991f1518f55ca9dbdada274ebcd245dc5e' 
  AND token = 'FvFR5GHJcGbaa+HiuTtqoofYQ+U295UE8R3QtVDqCIA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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