SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '11a5e345cd826a8ee3621e46b380715d740cad8bed5163739f4d60e0d36b4200' 
  AND token = 'BG0T0s/dwah+IbfrVt4GjCuOLNTPMNmVo3X9HFMfB4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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