SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'faf925ef10030df2b9b288106582bb67de673abd94b3aef931529d4076290343' 
  AND token = 'RbfgUoW2ud1OUdv6UexXh/M7qGjU5DvgKjzBKc9LJug=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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