SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '94b570adea516cf49729c42cf74b7b0f6af045ccbbaf712df0733c208ef64bd9' 
  AND token = 'TWXhtLiDsbgAkcjTSgWzLL8+ZuQApjKPD8kSv/W8w/Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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