SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a02a6e0d8c345ebee32e0a85e11950f30da5640c12218b6d9840e4797d0535d' 
  AND token = 'dA/VQIGbLjWVooWn4Gkl827RJrRRiKrZdIj+Y64sx9I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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