SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92417a43754606587d8fe787ab49630b6405f8c3f35fe45c6919595657282e52' 
  AND token = 'rg9W7J7i5xtz7G4FBxOpK/WKjZvx/qkd8eho8UTFo9Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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