SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7f00d86815a982bf0ba14beef68235a19fa42e8a8de73e9c5107fb265c5e2af' 
  AND token = 'cO/VQcrtqU02kKGNpTFnlVeHMUx+2akw8N3Ik4i8Lak=' 
  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"
    }
  }
}