SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '053ef12b5f112ddff802c14f904d243709333a67e28109440026a85081cfce96' 
  AND token = 'I7A1RY3USsPRZhBUPNtk4npa33OF+1g2DdZgJ3ehB8Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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