SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '466dbcdf4cc4d59d59f37f154a30ed211a1bf8ac7b49f59edcd45200502f5371' 
  AND token = 'lSQZpSsAYXMLqjmWRoZxYehvLpp14PzszhOyKgWRzwM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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