SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '462f73ae710fa40a6cfc374cb5e665557a18120fc035056db12efb4166e44ed7' 
  AND token = '2jOlz2YyuO+U2fDwb1ditOxU2MwpuB3uwAAgHlCpCi0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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