SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ff3dbc53f5df341fb796cf0008dbb8b618ad5787de592c02da1c9222eccd158f' 
  AND token = 'YgwFSdkZprt0Lod7rXAXid0nWIF0zKwkAp6Vou9VXwo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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