SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9594c0302fa0434cd380a9284a60401aaab88490596b39cdfae44323ac830e49' 
  AND token = 'IzXl3X90TVKldB5JDMLYVkA1GIQrLQPcR7eNCgfnvWs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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