SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ad95eb1ea1252b40a32fe7b8ef8ae98eccb0c526d68828ce102b385fb4a220bc' 
  AND token = 'vgLUjhcb3Aj/rDMTY4KVHnhVPSWyFxuYKJ0rBpXjHQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}