SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1e2d771cbb6b6bbf6e59fc35f9a7e4926c520231bdaa5515a4a790ce699b403b' 
  AND token = 'Pxfvi4IGC/f9AVuVIsrfKJrmi8zc4wS/ohLuBTzgwog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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