SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '655cfa18cd9a35e6acb3251ce91174d32aa2be09825defae3631624cdab0c91e' 
  AND token = 'Q4/UXeXiL8n3t96bn+tXfYNerf3RmfT+4uP7QhHN24Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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