SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf625b964e606c95ef2dcf153d9970ddc5dc8e3f50dfe05b592a7a1aff1498dc' 
  AND token = '7CkGXJBHQftFqQP/zEVd5zYRkBPvSyC+UthMTHjZCHk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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