SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aeb280ef4f9d035ab976bb278af312e09c89d02e26b11a96523bbe8e641d09dd' 
  AND token = '2p5Bq5a70cV3jIiXASxe/w3HUnWSybdJpSrSJjgPw7E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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