SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '343cf1d5ffb2bcfd61cdc9dd18671af16a2efab3d2bbf5aade37a3ef146775f9' 
  AND token = 'HspbwfAVix9TPpe0WYT+xKu9WAmxXDgU0f0r5vflS7c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00050

JSON explain

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