SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b0839494458c3067ed3e61652f6d620d2fdcfe2b6f1bb20bef49c82df7a59b4b' 
  AND token = 'YmuLaSEi7HWzXj6FnpIceHQUICl6c8IvKPKzMdn8pog=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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