SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18c441602c8e6afdc4efd85afd384cbe27aec91df68c386da695ae3066fe0bbd' 
  AND token = 'p8yxCalAD9DOZdbrtG0JudrJfslgkpwFZWkLJFklZhI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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