SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '23289381f46c09cafe07956698ed627528e99f8ecfec0d4657303b09651b4091' 
  AND token = 'XfGmJg0VlBs7wK5CFXPe9baRWEJzKElPyJPKB6cCTU0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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